Balanced slide-valve.



No. 663,936. Patented nec. la, |900.

' w. scHMoLKA.

BALANCED SLIDE VALVE.

(Application led Apr. 12, 1900.)

Patented Dec. I8, |900.

w. scHmoLKA, BALANCED SLIDE VALVE.

(Application led Apr. 12, 1900.)

2 Sheets-Sheet 2.

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me "mams PETERS co4. Pucaumo., wAswNnToN. u. c.

UNTTED STATES y PATENT Ustica.

VILHELM SCHMOLKA, OF POLA, AUSTRIA-HUN GARY.

BALANCED S LlDE-VALVE.

SPECIFICATION forming part of Letters Patent No. 663,936, dated December18, 1900.

Application filed April 12, 1900. Serial No. 12,513. (No model.)

To @ZZ whom t may concern:

Be it known that I, WILHELM SCHMOLKA, engineer in the Royal ImperialNavy, a citizen of the Empire of Austria-Hungary, residing at Pola,Austria-Hungary, have invented certain new and useful Improvements inBalanced Slide-Valves, of which the following is a specification.

This invention relates to improvements in slide-valves, the object beingto provide means for balancing plane slide-valves in engines of greathorse-power, and more especially those used in connection With marineengines.

The invention contemplates arranging the valve and slide in such Way asto effect the steam admission from beneath or from Within the valve,While the exhaust is effected outside the valve. The valve is thus givena tendency to move outwardly instead of being compressed upon its seat,as heretofore, under the tremendous pressure of live steam to which ithas been subjected. This outward movement, as it were, is retarded orbalanced by what I term pistons, which are pressed in any suitablemanner upon the valve, so that the latter is in perfect equilibriumbetween these two opposing forces.

The invention thus consists in the particular arrangement andcombination of parts of the slide valve hereinafter described Withreference to the accompanying drawings, which illustrate the inventionin its preferred form embodied in the Well-known Penn slidevalve, andWherein- Figure l is a longitudinal section through the steam-chest andslide-Valve. Fig. 2 is a plan view thereof, some of the parts appearingin section; and Fig. 3 is a cross-section on line A B,` Fig. 2. l

While I have mentioned steam as being the motive fluid, I have done somerely as an example for convenience in setting forth the nature of theinvention, it being obvious that any motive iiuid applicable to thepresent system of slide-valves can be employed with my improved system.

Referring to the drawings, a is the slidevalve, b the steam-chest, andCZ the condenser or exhaust-receiver. The valve a has the central portc, Which serves as the admission-port for the live steam, and thesteam-chest communicates with the exhaust or with a condenser d.

The constructional modications resulting from the reversing of theordinary arrangement of the slide-valve consist merely in adapting theadmission and exhaust ports to the same reversed order and causing theexternal lap of the steam-ports to take the place of the internal lap,and vice versa. The steam enters from the steam-chest b through port c,enters the cylinder by ports fu o, and is exhausted by ports w w.

To prevent the live steam Within thevalve ct from raising t-he latterfrom its seat on the cylinder-face, I provide a novel means, which inthe present instance consists of four pistons h, arranged in the form ofa square and having guides 'i fitting into stuffing-boxes in the upperportion of closed cylinders la, which latter are fixed in apertures ofthe valve-chest cover Z and adapted to be supplied with pressure bymeans of Water,compressed air, steam, or the like through suitable ductst. The pistons 7L are made hollow and have inner ribs or splines h andrectangular base plates or shoes r, the latter extending beyond andlaterally of the cylinders. Said base-plates are further reinforced byribs m and move in suitable guides n. The under surface of the shoes rare made plane and perfectly smooth to reduce friction to the leastpossible minimum, and suitable grooves are provided, as shown, forlubricating purposes. The pressure upon the pistons 7i is so regulatedas to balance the internal steam-pressure of the valve acting as acushion for the valve and at the same time forcing the latter upon itsseat with a suitable amount of pressure. The upwardly-directed pressureof the steam in the interior of the valve is balanced by the pistons h,and the pressure exerted by these latter upon the valve exceeds theinternal pressure by from five to ten per cent.

Having thus described my invention, I claim- 1. The combination with acylinder and a valve-chest, of a slide-valve provided with a cavity toreceive the motive fluid, ports to permit of the passage of the fluidfrom the cavity into the cylinder, and ports to permit of the passage ofthe exhaust fluid from the IOO cylinder through channels in the valve tothe exhaust or condenser, a rectangular cover for the Valve-chest having apertures, four closedtop cylinders fixed in apertures of thevalvechest cover arranged in the form of a square, four pressure-pistonsin said cylinders, and means for actuating said pistons, substantiallyas described.

2. The combination with the valve-chest cover having apertures, of theclosed-top pressure-cylinders fixed in said apertures, stuffing-boxes inthe upper portions of said cylinders,holloW pistons in said cylinders,guides on the pistons extending into the stuffingboxes, rectangularbase-plates on the bottoms of said pistons below and extending laterallybeyond the cylinders, and suitable guides and reinforcing-ribs for saidshoes, the under surfaces of said shoes being smooth and provided withlubricating-grooves, substantially as described.

In witness whereof I have hereunto signed my name, this 13th day ofFebruary, 1900, in the presence of two subscribing Witnesses. WILHELMSCHMOLKA. Witnesses:

LEONHARD RoEsLERZ, HANS HOFMANN.

